The long-term goal of this research is to understand the neural mechanisms underlying the perception of complex natural scenes in healthy and diseased visual systems. Unlike the stimuli used in traditional neurophysiological studies, most natural images are composed of multiple, frequently overlapping, objects. The ability to segment these images into component objects depends upon the detection and interpretation of regions of object overlap. This process is referred to as figure-ground interpretation. One objective of this proposal is to understand the neuronal basis of figure-ground interpretation. A physically salient object can be perceptually suppressed by the presence of another more salient object. This suppression underlies the ability to select one object as a target for action while ignoring other objects. A second objective of this proposal is to understand the neuronal mechanisms underlying this suppression. To achieve these objectives, a number of novel visual displays have been developed. To establish a correspondence between perceptual and neuronal events, a combination of behavioral and neurophysiological techniques will be used. Results from these experiments will lead to more refined models of visual processing and aid in the development of artificial sensory systems. In addition, this research will provide information for the treatment of brain-damaged and disease conditions that disrupt visual function.